\[\boxed{\text{216\ (216).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[x^{2} - 2ax + a^{2} - 4 = 0;\ \ \text{\ \ }\]
\[x_{1}\ и\ x_{2}\ меньше\ 5\]
\[D = 4a^{2} - 4a^{2} + 16 = 16\]
\[x_{1} = \frac{2a + 4}{2} = a + 2\]
\[x_{2} = \frac{2a - 4}{2} = a - 2\]
\[\left\{ \begin{matrix} a + 2 < 5 \\ a - 2 < 5 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ }\left\{ \begin{matrix} a < 3 \\ a < 7 \\ \end{matrix} \right.\ \]
\(\ \)
\[Ответ:a \in ( - \infty;3)\text{.\ }\]